1. Field of the Invention
The present invention relates to a pump and more particularly to a pump which can be employed in a wide variety of operative environments, but which is particularly well suited to construction in very small sizes operable to assist in the pumping of bodily fluids upon in vivo insertion in a selected fluid passageway such as the aorta of the human heart.
2. Description of the Prior Art
The technologies associated with the pumping of fluids are largely dependent upon the properties of the particular fluid to be pumped and the confines within which the pump must operate. While most pumps must operate within constraints as to size and capacity, there are certain applications in which these constraints are severely limiting. These problems are even more acute where human life may be dependent thereupon.
For example, it has been known to employ miniature blood pumps adapted for insertion into the vascular system of the human body to afford cardiac assistance during a period of trauma and recovery. Thus, it has been known in the event of left ventricular failure following open heart surgery or as the result of a mild cardial infarction to employ such pumps for intraarterial ventricular assist. Such pumps have been maneuvered into the left ventricle of the patient's heart by insertion through an incision in the patient's groin and passage of the pump assembly through the vascular system and into the left ventricle through the aorta. The pump is then driven from a location outside the patient's body by a motor to provide the desired blood flow. This avoids the necessity for a more radical procedure.
While experiments in these areas appear particularly promising, the limitations as to size and capacity of such pumps have interfered with their adoption and usage. Since the assembly is inserted at a site remote from the heart and must be maneuvered along a tortious course, the diameter of the pump itself restricts its use. In order to reduce the outer diameter of the pump to a size capable of such passage, the capacity of such pumps has had to be reduced to a level below that which would be preferred for optimum blood flow. As a consequence, the application of this technology has been limited.
Therefore, it has been known that it would be desirable to have a pump capable of manufacture in extremely small sizes capable of operating at capacities well above that heretofore achieved in pumps of equivalent size and which is particularly well suited to use in the vascular systems of the human body to supplement the flow of bodily fluids during times of trauma and recovery without the need for major surgery or other radical procedures.